Carry one more item in your backpack
You must have 2 class mods for this to work. Once your backpack is full, switch your currently equipped class mod for another one in your backpack (you can then re-equip your original class mod after you've done this). Then exit the backpack menu and you can now pick up one more item and have a backpack with 28 items in it instead of maximum 27.
True Vault Hunter Mode
Complete Normal difficulty story mode.
Minecraft enemies and outfit
In the Caustic Caverns underneath Sanctuary, near the furthest edge, there is a shallow incline. If you go along the left-most cliff beside the incline, you will find Minecraft blocks. Breaking them will lead into an area with creepers from the Minecraft games, a golden ore block with a normal outfit, and a special outfit for defeating the creepers.
To unlock extra wub, go to the title screen(where it says push start) and do the konami code, up up down down left right left right O X start. Under gameplay it will unlock extra wub, but sorry, it does literally nothing.
Get 2 players, then go into trade with each other. put the gun you want to trade then duel for it. Once you are into duel, drop the weapon you are trading for and let the other player pick up that weapon. Once that happens, win the duel. You win the weapon and the other player has the weapon.
Badass Rank Farming
To build a high Badass Rank, and gain all the perks associated with it, create a pair of new characters in co-op mode and have player 1 beat player 2 in 50 duels. This gives 166 Badass Ranks. Save and quit, then start another new game, creating another new character for player 1 (don't bother messing with player 2's character). Fight another 50 duels, with player 1 winning them all for 166 more Badass Ranks. Repeat as desired, and delete the pile of unwanted characters when you're done.. If you set the controller configuration to something where you can just keep tapping the melee-attack button without ruining your aim at the other player, you can finish a duel-run like this in roughly 10 minutes. Thus, over the course of one hour, you can build up 996 Badass Ranks.
Allowing secondary characters to reach level 20 easily. [Pre-Patch]
When you have a character reach Tiny Tina do all of her side missions until you make it to the final stage of her tea party. Here she wants you to lure Flesh-Stick to her little cove to join her tea party. Since you can fail this mission by killing him you can actually repeat that over n over for experience. On top of that if a second controller is available and you wish to make another character but don't want to level them up the normal way you can have that created person join your session and have them run all the way to Tiny Tina. If you keep them in front of her and your main character in front of where Flesh-Stick walks out you can kill him and re-accept the mission as fast as your trigger finger allows making anyone reach roughly 20-21 in a matter of minutes.
FOR PS VITA
On the title screen, if you do the Konami code (up,up,down,down,left,right,left,right,O,X,start) there will be an option that is titled "Extra Wub". It does absolutely nothing.
FOR XBOX 360
Easy ''Not Full Of Monkeys'' Challenge Levelling
"Not Full Of Monkeys" is a challenge that you meet by killing enemies with stationary barrels of any type. Well, with Gaige the Mechromancer DLC, you don't need the barrel! Anger a swarm of Rakks and summon the Deathtrap. They will rush you, and the Deathtrap will use it's laser to kill them. It counts as a stationary barrel this way. Try this on all flying enemies for some quick Badass rank!
Borderlands 1 Skin
If you have a save file for Borderlands 1 while playing Borderlands 2 you'll unlock characters skin from the previous game.
Enter the Konami code:up, up, down, down, left, right, left, right, B, A, Start, at the title screen to unlock Extra Wubs in the gameplay part of the options menu. Extra Wubs literally does nothing.
Minecraft Easter Egg
After Chapter 9, Go to Sanctuary Hole and jump off a cliff then and go to Caustic Caverns run northwest till you reach the Gurdian Ruins and go to the Minecarts and turn right, jump over the rectagular rocks and turn left. and yyou will find Minecraft Dirt, break though those and you will find Minecraft stone, cobblestone and coal. Break though those an there will be Creepers and blocks of gold, diamond, irridium and other surprises. Once you kill the badass creeper (yes thats really his name) you will get minecraft skins such as Steve Head and Steaves Cloths.
Unlimited fast badass ranks
Create a new character. Using a second controller, join the game as a guest. At the very beginning of the game, using your main account stand directly in front of the guest character and win 50 duels (melee with both controllers to start the duel, melee again with the main controller to win.) This will provide a total 166 badass ranks. You can then create another new character and repeat this process.
Beating Terramorphous Solo *Requires 2 Controllers*
To beat Terramorphous if you don't have Xbox live or don't like joining sessions, all you need to do is set up a split screen game with your main character and a second character. The second character's gear doesn't matter because he will not be involved in any combat. First, get to Terramorphous peak and have your second character drop into his lair without summoning Terramorphous. Far to the right of the horn you use to summon Terramorphous there will be a small ridge at the very corner of the map before the open cliff meets the rock face. If you run to this ridge you will see that you can crouch and walk out behind it, completely blocking all of Terramorphous's attacks. (Note: You can still do this after Terramorphous is summoned however it is much more difficult.) This character will serve as a placeholder so that when your main character dies you will not lose your progress facing Terramorphous and he will not regain all his health. Now when you are ready drop your main character down and summon Terramorphous. From there you may use any strategy to wear his health down, however I would recommend finding helpful Legendaries such as the Unkempt Harold and The Bee shield before attempting this. When you die, you will simply respawn and be able to drop back down and keep fighting Terramorphous without his health regenerating. If you do not want to lose money when you die, give it all to the second character (who will never take damage) first so that you recieve free respawns from the New-U station. Good luck and happy hunting!
Easy Thousand Cuts Farming
After accepting the quest "Rocko's Modern Strife" and heading to Thousand Cuts to start "Defend Slab Tower" you should notice that no foes will spawn in the area; as long as you don't progress through the quest. Since normal foes will no longer spawn, you are free to circle the area and loot every chest without being hindered by enemies. However, foes like one-armed bandits and loot midgets will still spawn. If you save and exit after clearing all the chests, you can simply accept "Defend Slab Tower" once again and clear them out as many times as you like with the same conditions as long as you don't complete the quest.
Easy XP during Tiny Tina's Tea Party Mission (Pre-Patch)
At the end of Tiny Tina's Tea Party side quest you're required to lure a psycho named "Flesh Stick" back to her home. If you shoot and kill Flesh Stick rather than luring him back you'll reap a huge XP boost (750xp/kill on level 18 and around 1,800xp on level 17) which can be repeated by simply talking to Tiny Tina again and restarting the mission. This exploit works best during co-op play. where one person stations where Flesh Stick spawns and another at Tiny Tina. Doing so will enable you to repeat this process in quick succession until the game will no longer spawn Flesh Stick again. At this point you can run back to the start of the area, exit and return, or (faster), save & quit then reload the game. Doing so will allow Flesh Stick to respawn again.